Seal chain having greaser

ABSTRACT

A greasing through hole  20   1  is perforated through one outer link plate  3   1  and greasing means  21  is attached to the through hole. Degreasing through holes  20   2  and  20   3  are perforated through an outer link plate  3   2  or an inner link plate  2   2  on the side distant from the outer link plate with a bearing section A between and degreasing means  22  are attached to those through holes. Lubricant injected from the greasing means  21  is supplied to the bearing section A through a gap c between the sealing means  6  and the outer link plate  3  and used lubricant within the bearing section A is discharged out of the degreasing means  22  through another gap c.

TECHNOLOGICAL FIELD

The present invention relates to a conveyor or power transmission sealchain and more specifically to a seal chain suitable especially as aconveyor seal chain. Specifically, the invention relates to a seal chainhaving a greaser for supplying lubricant such as grease and oil to abearing section sealed by sealing means.

BACKGROUND ART

Hitherto, sealing means 6 is disposed between an inner link plate 2 andan outer link plate 3 so as to surround a bush 5 in a seal chain 1′ asshown in FIG. 8 for example. Lubricant such as grease is sealed in abearing section A composed of the bush 5 and the pin 7 by the sealingmeans to keep flexibility of the chain smooth for a long period of timeon the basis of relative rotation of the bush 5 and the pin 7. Becausedusts caused by bulk materials such as grains, coals, iron ores, limeand salt readily invade into the bearing section A in the unloading sealchain 1′ such as a bucket conveyor for conveying such bulk materials,there has been proposed to provide two rows of sealing members 6A and 6Bhaving O-rings 12 and 13 that contact the inner and outer link plate 2and 3, respectively, and metallic holding plates 15 and 16 for holdingthe O-rings (see JP Patent Application Laid-open No. 2002-160818).

As shown in FIG. 8, the seal chain 1′ is provided with a greaser 11having an oil orifice 9 of a predetermined length perforated through thecenter of the pin 7 in a longitudinal direction from one end face of thepin 7, a grease nipple 10 attached at an opening of the hole andcommunication holes 9 a (the oil orifice 9 and the communication holes 9a will be referred to as greasing holes or greasing paths hereinafter)formed toward the bearing section A from the grease orifice. Then, thegreaser 11 supplies grease or the like to the bearing section A throughthe relatively long greasing holes 9 and 9 a from the grease nipple 10at one end face of the pin 7. Furthermore, in order to prevent theO-rings 12 and 13 of the sealing member from bursting by greasingpressure in supplying grease, the ringed holding member 15 or 16 of thesealing member is provided with an oil groove (or gap) formed into ashape of concave groove or the like for releasing the pressure (notshown).

DISCLOSURE OF THE INVENTION

In replenishing grease or the like by the greaser 11, there has been acase when the grease or the like solidifies on the way of the greasingpath, thus clogging the greasing paths 9 and 9 a and disabling to supplythe grease, because the greasing paths 9 and 9 a are long in the priorart seal chain 1′. This phenomenon is apt to occur in a large conveyorchain whose greasing path is long and which is not greased so often andtherefore the grease stays at the bearing section and is apt to solidifydue to chemical changes such as deterioration.

Furthermore, because the prior art seal chain 1′ has the oil groove orthe gap for releasing the greasing pressure, it is unable to completelyseal the bearing section A by the sealing means, so that the lubricantalways leaks from the bearing section A, requiring operations ofreplenishing the lubricant by the greaser 11 relatively soon and ofcumbersome maintenance. Furthermore, there is a case of bursting thesealing means because the large pressure is apt to act on the basis ofthe long greasing paths in replenishing the grease or the like from thegreaser 11 and the oil groove or the like described above is unable torelease the large pressure that acts suddenly.

Still more, because the greasing holes 9 and 9 a are formed within thepin 7 on which large bending and shearing stresses act during when theseal chain 1′ is in operation, there is a risk of damaging the pin dueto concentration of stresses. In order to avoid such risk, pins having alarge diameter are used in designing the seal chain. Along that,however, the seal chain requires bushes and rollers having a largediameter and due to that, requires also link plates having a largethickness or width, hindering lightening and cost-down of the chains.

Accordingly, it is an object of the invention to provide a seal chainthat allows lubricant to be replenished directly to a lubricant holdingpart that is sealed by sealing means and that thereby solves theaforementioned problems.

The present invention is characterized in that in a seal chain (1, 1 . .. ) in which an outer link (17) having a pair of pins (7, 7) and outerlink plates (3, 3) coupled by these pins are alternately linked with aninner link (18) having a pair of bushes (5, 5) and inner link plates (2,2) coupled by these bushes by inserting said pins through said bushesand sealing means (6, 6) are interposed between the outer link plate andthe inner link plate so as to seal lubricant to a bearing sectioncomposed of the pin and the bush:

a greasing through hole (20 ₁) is perforated through said outer linkplate (3 ₁) so as to communicate with said bearing section (A); and

greasing means (21) capable of supplying the lubricant from the side ofan outer face of said outer link plate to said bearing section isattached to said through hole.

Thereby, the lubricant is supplied to the bearing section directly andefficiently because the greasing path from the greasing means to thebearing section is short. Furthermore, faults in greasing to the bearingsection may be reduce because clogging of greasing holes due tosolidification of the lubricant such as grease hardly occurs.

Furthermore, degreasing through holes (20 ₂, 20 ₃, 20 ₄) are perforatedthrough said outer link plate (3 ₂: see FIGS. 1, 6 and 7 for example) orthrough an inner link plate (2 ₂: see FIGS. 4 and 5 for example) on theside separated from said greasing means (21) with said bearing section Abetween; and

degreasing means (22) for discharging the lubricant within said bearingsection when lubricant is supplied from said greasing means (21) isattached to said through hole.

Thereby, it becomes easy to discharge the used lubricant within thebearing section out of the degreasing means, to replace with the newlubricant in the bearing section when the lubricant is supplied by thegreasing means and to maintain the lubricant performance of the bearingsection of the seal chain for a long period of time. Furthermore,because pressure applied in injecting the lubricant from the greasingmeans is released from the degreasing means and no excessive pressureacts on the sealing means, it becomes possible to prevent a failure suchas burst of the sealing means from occurring.

Furthermore, the provision of the degreasing means makes it possible toeliminate a releasing groove or gap from the sealing means that havebeen necessary in the prior art chain, to reduce a leak of lubricantduring normal use, to keep the lubricant in the bearing section for along period of time and to prolong maintenance intervals.

It is noted that while the words of greasing means and degreasing meanshave been used because grease is generally used as the lubricant, it ispossible to use oil and the like other than grease as the lubricant.Accordingly, the words of greasing or degreasing in the invention arenot necessarily mean to limit to grease.

Furthermore, said greasing and/or degreasing through holes (20, . . . )are disposed at parts between said pair of pin holes (3 a) of said outerlink plate (3) and within a width of diameter (D) of said pin hole (seeFIG. 2) or at parts between bush holes (2 a) of the inner link plate (2)and within a width of diameter (D) of said bush (see FIG. 4).

The parts of the through holes of the both of the outer link plate andinner link plate are parts distant from a region to which compressiveconcentrated stress of the pin hole or bush hole acts and from a leastprofile part that is liable to become a rupture face due to tensileforce acting on the chain and are parts less influenced by platestrength. Therefore, strength of the link plate will not drop due to thethrough holes. Thereby, it provides advantages in terms of strength andmachining as compared to those of the prior art in which greasing holeis perforated through a pin. Then, it becomes possible to lighten theseal chain and to lower the cost thereof.

Specifically, as shown in FIGS. 1, 4 and 5 for example, said bush (5) iscoupled with said inner link plate by protruding a certain degree out ofthe outer face of said inner link plate (2) and said sealing means (6, 6₂) have two rows of sealing members (6A, 6B) in a radial direction so asto surround the protruding portion (5 a) of said bush. Said inner andouter diametric sealing members (6A, 6B) have O-rings (12, 13) andringed holding members (15, 16) for holding the O-rings, respectively,said inner and outer diametric holding members abut from each other soas to keep said O-rings to contact with said inner and outer linkplates, the sealing means (6, 6 ₂) are positioned in a chain widthdirection (longitudinal direction of the pin) and are disposed so that apredetermined gap (c) exists between the back face of its holding memberand the inner face (b) of the outer link plate (3)(see FIG. 1) orbetween an outer face (f) of the inner link plate (2 ₂, 22 ₃) (see FIGS.4 and 5).

Furthermore, as shown in FIGS. 6 and 7, a ringed concave groove (27) isformed on the side of outer diameter of said greasing and degreasingthrough holes (20, . . . ) on the inner face (b) of said outer linkplate (3), said sealing means (6 ₃) has a ringed plate member (25) andan O-ring (26) held by the concave groove (27) of said outer link plateand the O-ring is arranged so as to contact with said plate member acertain gap (c) is created between said plate member (25) and the innerface of the outer link plate (3).

Thereby, the lubricant injected from the greasing means (21) is suppliedto the bearing section (A) through one gap (c) and the used lubricantwithin the bearing section (A) is discharged out of the degreasing means(22) through the other gap (c).

It is noted that the O-ring means a sealing member having a circularshape (ringed, O-shaped) made of elastic material such as rubber andit's sectional shape is not limited to be circular (O-shape) and mayhave a lip such as a shape of X, a shape of V, a shape of U and a shapeof W.

Furthermore, as shown in FIG. 7 for example, it is possible to provideroller sealing means (32) for sealing lubricant in a bearing section (B)of a roller (17) and to create through holes through the bush (5) tocommunicate the bearing section (A) for bending of the chain with theroller bearing section (B).

It is noted that while the reference numerals within the parentheses areprovided for the purpose of collating with the drawings, they will notaffect the description of Claims at all.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section view showing a seal chain of the present invention.

FIG. 2 is a front view thereof.

FIG. 3 is a back view thereof.

FIG. 4 is a section view showing the seal chain partially modified.

FIG. 5 is a section view showing the seal chain partially modifiedfurther.

FIG. 6 is a section view showing a seal chain of another embodiment.

FIG. 7 is a section view showing the seal chain of the other embodimentpartially modified

FIG. 8 is a section view showing a prior art seal chain.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of a seal chain of the invention applied to a continuousunloading conveyor chain will be explained below. As shown in FIGS. 1through 3, the seal chain 1 is composed of inner links 17 in which bothends of two inner link plates 2 and 2 are coupled by a pair of bushes 5and 5 and outer links 18 in which both ends of two outer link plates 3and 3 having the same shape are coupled by a pair of bushes 7 and 7. Aroller 19 is idly and rotatably fitted with the bush 7. Then, the chainis constructed by idly fitting the pin 7 into the bush 5 to alternatelyand endlessly link the inner link 17 and the outer link 18. The pin 7has a head 7 a having a large diameter at one end thereof and has atapered other end through which a through hole is perforated. The pin 7is inserted through a pin hole 3 a of one outer link plate 3 ₁ andpenetrates through the bush 5 such that its edge protrudes out of a pinhole 3 a of the other outer link plate 3 ₂. Then, a cotter pin 24 isinserted into the aforementioned through hole so that the pin will notcome off.

The both ends of the bush 5 protrude out of the inner link plates 2 by acertain degree and the sealing means 6 and 6 are interposed between theinner link plate 2 and the outer link plate 3 so as to surround theprotruding portions 5 a and 5 a of the bush. The seal chain 1 freelybends by a bearing section A arranged between the pin 7 and the bush 5so that the inner link 17 and the outer link 18 relatively rotate. Thesealing means 6 maintains the bending of the chain smoothly for a longperiod of time by sealing the lubricant such as grease supplied to thebearing section A and by preventing dusts and others from invading fromthe outside.

The sealing means 6 is composed of sealing members 6A and 6B disposed intwo rows in a radial direction. Each one has an O-ring 12 or 13 made ofan elastic member such as rubber and a holding member 15 or 16 forholding the O-ring. These holding members 15 and 16 are made of metallicringed members and have ringed concave grooves 15 a and 16 a formed forholding the O-rings, respectively, on different sides thereof. Forexample, the concave grooves are formed by implementing a soft nitridingtreatment (Tufftride treatment) on steel members such aschromium-molybdenum steel (e.g., SCM435 or SCM440) for the purposes ofsurface hardening and rust-prevention. It is noted that the materialsare not limited to those described above and fluorine coating may bealso implemented. Furthermore, although self-lubricant materials such assynthetic resin, oil impregnated sintered metal, bronze, phosphorbronze, linarite and others may be used, it is preferable to use lowfrictional materials including steel on which the Tufftride treatmenthas been implemented as described above. It is also noted that O-rings15 and 16 are not limited to those having the circular shape in sectionand may be those having other sectional shapes such as a shape of X insection (X-ring), a shape of V in section (V-ring), a shape of U insection (U-ring) and a shape of W in section (W-ring).

The inner diametric sealing member 6A is arranged so that the O-ring 12contacts with the inner link plate 2 and the outer diametric sealingmember 6B is arranged so that the O-ring 13 contacts with the outer linkplate 3. The both holding members 15 and 16 have abutting faces 15 b and16 b that abut from each other so as to maintain the contacts of theO-rings. That is, the inner diametric holding member 15 has a flangethat is flush with a face having the O-ring holding concave groove 15 a(the face facing to the inner link plate 2), that has a thickness ofabout a half and that protrudes in an outer diametric direction and theouter diametric holding member 16 has a flange that is flush with a facehaving the O-ring holding concave groove 16 a (the face facing to theouter link plate), that has a thickness of about a half and thatprotrudes in an inner diametric direction. These both flanges abut eachother, composing the abutting faces 15 b and 16 b described above.

The inner and outer diametric sealing members 6A and 6B are integratedin a width direction of the chain (in a longitudinal direction of thepin) by the abutment of the abutting faces 15 b and 16 b describedabove. Furthermore, the O-ring holding concave groove 16 a of the outerdiametric holding member 16 is formed to be deeper than the innerdiametric holding concave groove 15 a, so that a predetermined gap c iscreated between a face a of the both holding members 15 and 16 that arearranged so as to be substantially flush on the side of the outer linkplate and an inner face b of the outer link plate 3. It is noted that aslight gap is created between a face d of the both holding members 15and 16 that are substantially flush on the side of the inner link plateand an outer face e of the inner link plate 2.

Then, greasing or degreasing through holes 20 ₁ or 20 ₂ is formedthrough a part of the outer link plate 3 communicating with the bearingsection A, or more specifically through the part on the inner diametricside of the outer diametric O-ring 13 or more preferably through thepart corresponding to the gap c. These through holes 20 . . . havecounter bores 20 ₁a and 20 ₂a having a large diameter and formed to amiddle part of the thickness from one side. As shown in detail in FIGS.2 and 3, one outer link plate 3 ₁ is assembled such that the counterbore 20 ₁a faces to the outer face of the plate and the other outer linkplate is assembled such that the counter bore 20 a faces to the innerface of the plate. The both outer link plates 3 ₁ and 3 ₂ are the sameones and the through holes 20 ₁ and 20 ₂ having the counter bores 20 ₁aand 20 ₂a are disposed at parts between the both pin holes 3 a andwithin a chain width of the pin holes having a diameter D (slanted lineparts in FIG. 2). These parts are parts distant from parts where theouter link plate 3 may cause a rupture due tensile force acting on theseal chain 1, i.e., parts distant from weak parts in strength wherestress is concentrated from around a least profile of the pin hole ofthe link plate in a longitudinal direction of the plate and are partswhere the through holes 20 ₁ and 20 ₂ may not become starting points ofrapture and other.

A grease nipple 21 composing the greasing means is attached to thecounter bore 20 ₁a opening to the outer face of the outer link plate 3 ₁and degreasing means 22 is attached to the counter bore 20 ₂a opening tothe inner face of the other outer link plate 3 ₂. The greasing greasenipple 21 has a check valve for preventing the flow of grease to theoutside from the bearing section A side (grease sealing side). The checkvalve enables one to inject the grease or the like to the bearingsection side by effecting predetermined pressure by a grease gun.Furthermore, the same grease nipple with the greasing means describedabove is used for the degreasing means 22. A check valve is disposedalso in the degreasing grease nipple 22 so as to stop a flow from theoutside to the bearing section Aside. The check valve opens whenpressure of used grease within the bearing section A increases topredetermined pressure due to the injection of grease from the greasingmeans and discharges the used grease within the bearing section A.

When the same grease nipples are used for the greasing means 21 and thedegreasing means 22, it becomes easy to manage and to assemble the partsbecause the same one may be used for one and the other outer link plates3 ₁ and 3 ₂. However, it is not necessary to always use the same ones.For example, one that opens at low pressure than the greasing means 21may be used for the degreasing means 22 by taking fluid resistance ofthe grease within the bearing section A into account.

Because the seal chain 1 is constructed as described above, lubricantsuch as grease is filled into the bearing section A and the sealingmeans 6 and 6 seal it. Accordingly, the lubricant rotates the pin 7 andthe bush 5 of the bearing section A relatively and smoothly, thuskeeping smooth bending of the inner and outer links 15 and 16 in theseal chain 1. At this time, the inner diametric sealing member 6A turnsin a body with the inner link plate 2 because the O-ring 12 made ofrubber having a high friction constant contacts with the inner linkplate 2 and the outer diametric sealing member 6B turns in a body withthe outer link plate 3 because the O-ring 13 contacts with the outerlink plate 3.

Thereby, although the inner and outer holding members 15 and 16relatively rotate at the abutting faces 15 b and 16 b, these holdingmembers 15 and 16 are made of hard materials such as metal and thelubricant is interposed between them, so that their friction resistanceis smaller than a contact coefficient of the O-ring made of rubber andthe like and the link plate and will not hamper the smooth bending ofthe chain. Then, the O-rings 12 and 13 press-contact with the differentinner and outer link plates 2 and 3 without relatively rotating, so thatthey reduce a leak of lubricant within the bearing section A to theoutside, prevent dusts such as powders of iron ore, coals and cokes frominvading and keep the smooth bending of the chain for a long period oftime.

Then, at the time of maintenance of every predetermined use time, thegrease gun is applied to the greasing grease nipple 21 from the outsideof the seal chain 1 to inject grease at predetermined pressure. Thegrease injected from the grease nipple 21 flows into the bearing sectionA through the gap c, increases the pressure of the used grease in thebearing section A and opens the degreasing grease nipple 22 to dischargethe used grease. At this time, a clog of the greasing hole hardly occurseven if the grease is solidified because the greasing grease nipple 21and the degreasing grease nipple 22 are both disposed near the bearingsection A where pressure may be applied directly to the bearing section.Furthermore, the used grease is completely replaced with the new greaseand no lubricant failure occurs due to the remained used grease becausethe greasing means 21 and the degreasing means 22 are positioned on theopposite sides from each other with the bearing section A between. Stillmore, there is no possibility of bursting the sealing members 6A and 6Bbecause the pressure in injecting the grease escapes from the degreasingmeans 22 on the opposite side.

Next, a partially modified embodiment will be explained based on FIGS. 4through 7. It is noted that the same components with those in theprevious embodiment will be denoted by the same reference numerals andan explanation thereof will be omitted.

FIG. 4 shows the embodiment in which the degreasing nipple 22 isattached to the inner link plate 2. As compared to the previousembodiment, while the greasing means 21 and the sealing means 6 on theside of the greasing means (upper part in the figure) of the O-ring 12are the same, the degreasing means 22 is different from the sealingmeans 6 ₂. That is, a through hole 20 ₃ is perforated through the innerlink plate 2 ₂ on the side distant from the greasing means 21 with thebearing section A between so that the counter bore 20 ₃a faces to theside of the sealing means 6 ₂ and the grease nipple 22, i.e. degreasingmeans, is attached to the through hole 20 ₃ from the counter bore 20 ₃a.The same one with the grease nipple on the greasing side is used for thedegreasing grease nipple 22.

The sealing means 6 ₂ on the side of the degreasing means is disposed sothat the O-ring 12 of the inner sealing member 6A contacts with theouter link plate 3 and the O-ring 13 of the outer sealing member 6Bcontacts with the inner link plate 2 ₂. That is, although the sealingmeans on the greasing side and the sealing means on the degreasing sideare disposed so as to be mirror-symmetrical (back to back) from eachother in the previous embodiment, the both sealing means 6 and 6 ₂ aredisposed so as to face in the same direction (parallel) in this sealchain 1 ₂. Thereby, while the sealing means 6 on the greasing side hasthe gap c between the outer link plate 3 in the same manner with theprevious embodiment, the sealing means 6 ₂ on the degreasing side has agap c between an outer face f of the inner link plate 2 ₂.

Still more, the through holes 20 ₂ are disposed at a face between thepair of bush holes 2 a of the inner link plate 2 ₂, within a width ofdiameter D₂ of the bush hole and corresponding to the gap c, i.e., onthe inner diametric of the outer O-ring 13 in the same manner with theprevious embodiment (see FIG. 2). Thereby, an influence of the throughhole 20 ₃ given to the strength of the inner link plate 2 ₂ isminimized.

When grease is injected by the grease gun through the greasing greasenipple 21, the new grease flows into the bearing section A through thegap c and the used grease in the bearing section is pushed out to theopposite side and is discharged out of the degreasing grease nipple 22through the gap c.

FIG. 5 shows a still modified embodiment in which degreasing meansdiffers from the O-ring 12 shown in FIG. 4. In the seal chain 1 ₃, athrough hole 20 ₄ that is larger than the through hole 20 ₁ on thegreasing side is perforated through the inner link plate 2 ₃ on thedegreasing side. Then, the inner link plate 2 ₃ is assembled so that acounter bore 20 ₄a of the through hole 20 ₄ faces in the inner side ofthe chain (on the opposite side from FIG. 4) and a grease nipple 22 ₂,i.e., degreasing means, is attached from the side of the counter bore 20₄. The grease nipple 22 ₂ is of a relief valve type larger than thegrease nipple 21 on the greasing side and opens at relatively lowpressure to discharge the used grease within the bearing section A at arelatively large flow rate.

It allows a large amount of the used grease to be discharged at lowresistance out of the large degreasing grease nipple 22 ₂ at relativelylow pressure when grease is injected from the greasing side greasenipple 21 and troubles such as clog of the grease and burst of thesealing members to be reduced. It is noted that the large degreasinggrease nipple 22 ₂ is applicable not only to the present embodiment butalso to the seal chain 1 shown in FIG. 1

FIG. 6 is a section view showing an embodiment in which the sealingember is modified. Similarly to the embodiment shown in FIG. 1, thegreasing grease nipple 21 and the degreasing grease nipple 22 areattached to the outer link plate 3. The sealing means 6 ₃ is composed ofa ringed plate (plate member) 25 and an O-ring 26. The plate 25 is madefrom metal or synthetic resin that are low frictional materialssimilarly to the holding members (15, 16) described above. A ringedconcave groove 27 is formed on the outer link plate 3 so as to surroundthe pin 7 and the ringed concave groove 27 holds the O-ring 26. Theplate 25 is secured by the protruding portion 5 a and the O-ring 26contacts with the plate 25, thus creating a gap c between the plate 25and an inner face b of the outer link plate 3 and a seal of the bearingsection A. It is noted that the O-ring 26 is not limit to be circular insection and may have a lip such as shapes of X, V, U and W.

A through hole 20 ₅ perforated through the other outer link plate 3 ₁has the same diameter (that is, it has no counter bore) and is attachedwith the grease nipple 21, i.e., greasing means, from the outer side ofthe outer link plate 3 ₁. Accordingly, the grease nipple is attached tothe counter bore so that the grease nipple does not protrude out of thelink plate in the other embodiments, the grease nipple 21 of thisembodiment protrudes out of the outer face of the link plate.

In the seal chain 1 ₄, grease is similarly supplied to the bearingsection A through the gap c and used grease within the bearing section Ais discharged out of the degreasing grease nipple 22 through the gap con the opposite side also when the new grease is supplied from thegreasing grease nipple 21. Then, the O-ring 26 made of rubber is held ina body by the outer link plate 3 and rotates relatively with the plate25 integrated with the bush 5 when the seal chain 1 ₄ bends.

It is noted that in the present embodiment, although the greasing means21 is disposed on the side of the edge of the pin 7 and the degreasingmeans 22 is disposed on the side of the head 7 a of the pin 7, it ispossible to arbitrarily set whether the greasing means or the degreasingmeans is disposed on which side. Furthermore, while the chamfer 7 c isformed on the pin 7 to stop turning between the outer link plate 3, itis also applicable to the other embodiments.

FIG. 7 shows a seal chain 15 according to an embodiment in which sealingmeans is disposed also in a roller 19. The other parts are the same withthe seal chain 1 ₄ shown in FIG. 6. A disk-like shallow recess 20 havinga predetermined radius is formed on an inner face of the inner linkplate 2 ₃ and a ringed concave groove 31 centering on the bush 5 isformed on a bottom face of the recess 30.

The roller sealing means 32 is similar to the bush sealing means 6 ₃ andhas a ringed plate (plate member) and an O-ring 35. The 35 is held bythe concave groove 31, the plate 33 is secured by an end of the roller19 and the whole sealing means 32 is stored within the recess 30.

Then, lubricant such as grease is supplied to a bearing section Bbetween the roller 19 and the bush 5 and the sealing means 32 seals it.Thereby, similarly to the bearing section A between the bush 5 and thepin 7, it enables the roller 19 to smoothly turn with respect to thebush 5, smoothes engagement with a sprocket, lowering noise, and canmaintain this state for a long period of time.

In the present embodiment, a plurality of through holes 36 is formedthrough the bush 5 so that the both bearing sections A and Bcommunicate. Thereby, when the grease is supplied to the bearing sectionA by injecting the grease from the greasing grease nipple 21, a part ofthe grease is supplied also to the bearing section B via the throughholes 36. At this time, although used grease within the bearing sectionA is discharged out of the degreasing nipple 22, used grease within thebearing section B is discharged out between the O-ring 35 and the plate33.

It is noted that a degreasing grease nipple may be provided incorresponding to the sealing means 32 of the inner link plate 2. It isalso needless say that it is possible to arrange so that no lubricant issupplied to the bearing section B without creating the through holes 36.

INDUSTRIAL APPLICABILITY

While the seal chain of the invention is suitably used as an endlessunloading conveyor chain such as a bucket elevator and a pan conveyorfor continuously conveying bulks by attaching buckets, the use thereofis not limited to that and may be used as other conveyor chains such aslat conveyor, a slab conveyor and other conveyor for water treatment,for raking, for sand sedimentation and sedimentation pond and for a dustconveyor. It is also similarly applicable to a power transmitting sealchain such as those for motorcycles and timing chains.

1. A seal chain wherein an outer link having a pair of pins and outerlink plates coupled by these pins is alternately linked with an innerlink having a pair of bushes and inner link plates coupled by thesebushes by inserting said pins through said bushes and sealing means isinterposed between the outer link plate and the inner link plate so asto seal lubricant to a bearing section composed of the pin and the bush,characterized in that: a greasing through hole is perforated throughsaid outer link plate so as to communicate with said bearing section;and greasing means capable of supplying the lubricant from the side ofan outer face of said outer link plate to said bearing section isattached to the through hole.
 2. The seal chain according to claim 1,wherein a degreasing through hole is perforated through said outer linkplate on the side separated from said greasing means with said bearingsection between; and degreasing means for discharging lubricant of saidbearing section when lubricant is supplied from said greasing means isattached to said through hole.
 3. The seal chain according to claim 1,wherein a degreasing through hole is perforated through said inner linkplate on the side separated from said greasing means with said bearingsection between; and degreasing means for discharging lubricant of saidbearing section when lubricant is supplied from said greasing means isattached to said through hole.
 4. The seal chain according to claim 1,wherein said greasing through holes are disposed at parts between saidpair of pin holes of said outer link plate and within a width ofdiameter of said pin hole.
 5. The seal chain according to claim 2,wherein said greasing through holes are disposed at parts between saidpair of pin holes of said outer link plate and within a width ofdiameter of said pin hole.
 6. The seal chain according to claim 3,wherein said through holes are disposed between said pair of bush holesof said inner link plate and within a width of diameter of said bushhole.
 7. The seal chain according to claim 2, wherein said bush iscoupled with said inner link plate by protruding by a certain degree outof an outer face of said inner link plate; said sealing means has tworows of sealing members in a radial direction so as to surround theprotruding portion of said bush; said inner and outer diametric sealingmembers have O-rings and ringed holding members for holding the O-rings,respectively; said inner diametric and outer diametric holding membersabut from each other so as to keep said respective O-rings to contactwith said inner and outer link plates; the both sealing means on theside where said greasing means is disposed and on the side where saiddegreasing means is disposed are arranged so that the O-ring of saidinner diametric sealing member contacts with said inner link plate andthe O-ring of said outer diametric sealing member contacts with saidouter link plate; and said both sealing means are disposed so that saidpredetermined gap exists at least between the back face of said innerdiametric holding member and an inner face of said outer link plate 8.The seal chain according to claim 3, wherein said bush is coupled withsaid inner link plate by protruding a certain degree out of an outerface of said inner link plate; said sealing means has two rows ofsealing members in a radial direction so as to surround the protrudingportion of said bush; said inner and outer diametric sealing membershave O-rings and ringed holding members for holding the O-rings,respectively; said inner and outer diametric holding members abut fromeach other so as to keep said respective O-rings to contact with saidinner and outer link plates; the O-ring of said inner diametric sealingmember contacts with said inner link plate and the O-ring of said outerdiametric sealing member contacts with said outer link plate in thesealing means on the side where said greasing means is disposed; theO-ring of said inner diametric sealing member contacts with said outerlink plate and the O-ring of said outer diametric sealing membercontacts with said inner link plate in the sealing means on the sidewhere said degreasing means is disposed; the sealing means on the sidewhere said greasing means is disposed is disposed so that saidpredetermined gap exists at least between the back face of said innerdiametric holding member and the inner face of said outer link plate;and the sealing means on the side where said degreasing means isdisposed is disposed so that said predetermined gap exists at leastbetween the back face of said inner diametric holding member and theouter face of said inner link plate.
 9. The seal chain according toclaim 2, wherein said bush is coupled with said inner link plate byprotruding a certain degree out of an outer face of said inner linkplate; ringed concave grooves are formed on the side of the outerdiameter of said greasing and degreasing through holes on the inner faceof said outer link plate; and said sealing means has a ringed platemember fixed by the protruding portion of said bush and an O-ring heldby the concave groove of said outer link plate, and said O-ring isdisposed so as to contact with said plate member and to create a certaingap between said plate member and the inner face of said outer linkplate.
 10. The seal chain according to claim 1, further comprising aroller rotatably and idly fitted to said bush; roller sealing meansinterposed between said inner link plate and said roller so as to seallubricant with a roller bearing section composed of said bush and saidroller; and a communicating section for communicating said bearingsection and said roller bearing section.